Yargs

Yargs be a node.js library fer hearties tryin’ ter parse optstrings

Description

Yargs helps you build interactive command line tools, by parsing arguments and generating an elegant user interface.

It gives you:

commands and (grouped) options (my-program.js serve --port=5000).
a dynamically generated help menu based on your arguments.

bash-completion shortcuts for commands and options.
and tons more.

Installation

Stable version:

npm i yargs

Bleeding edge version with the most recent features:

npm i yargs@next

Usage

Simple Example

#!/usr/bin/env node
const {argv} = require('yargs')

if (argv.ships > 3 && argv.distance < 53.5) {
  console.log('Plunder more riffiwobbles!')
} else {
  console.log('Retreat from the xupptumblers!')
}

$ ./plunder.js --ships=4 --distance=22
Plunder more riffiwobbles!

$ ./plunder.js --ships 12 --distance 98.7
Retreat from the xupptumblers!

Complex Example

#!/usr/bin/env node
require('yargs') // eslint-disable-line
  .command('serve [port]', 'start the server', (yargs) => {
    yargs
      .positional('port', {
        describe: 'port to bind on',
        default: 5000
      })
  }, (argv) => {
    if (argv.verbose) console.info(`start server on :${argv.port}`)
    serve(argv.port)
  })
  .option('verbose', {
    alias: 'v',
    type: 'boolean',
    description: 'Run with verbose logging'
  })
  .argv

Run the example above with --help to see the help for the application.

Supported Platforms

TypeScript

yargs has type definitions at @types/yargs.

npm i @types/yargs --save-dev

See usage examples in docs.

Deno

As of v16, yargs supports Deno:

import yargs from 'https://deno.land/x/yargs/deno.ts'
import { Arguments, YargsType } from 'https://deno.land/x/yargs/types.ts'

yargs()
  .command('download <files...>', 'download a list of files', (yargs: YargsType) => {
    return yargs.positional('files', {
      describe: 'a list of files to do something with'
    })
  }, (argv: Arguments) => {
    console.info(argv)
  })
  .strictCommands()
  .demandCommand(1)
  .parse(Deno.args)

ESM

As of v16,yargs supports ESM imports:

import yargs from 'yargs'
import { hideBin } from 'yargs/helpers'

yargs(hideBin(process.argv))
  .command('curl <url>', 'fetch the contents of the URL', () => {}, (argv) => {
    console.info(argv)
  })
  .demandCommand(1)
  .argv

Usage in Browser

See examples of using yargs in the browser in docs.

Community

Having problems? want to contribute? join our community slack.

Documentation

Supported Node.js Versions

Libraries in this ecosystem make a best effort to track Node.js’ release schedule. Here’s a post on why we think this is important.